Successive approximation analog-to-digital conversion device skipping comparison results and its operating method
The analog-to-digital conversion device includes a signal generating unit that generates a plurality of comparison voltages based on an analog input voltage and generates a plurality of comparison results of the plurality of comparison voltages based on a sampling period, a calculation unit that skips a comparison result generated by a comparison voltage having a smallest difference between the analog input voltages among the plurality of comparison voltages from the plurality of comparison results and generates an end of comparison based on a remaining plurality of comparison results, and a SAR logic unit that generates a digital signal corresponding to the end of comparison and stores information for each bit of the digital signal.
1 . An analog-to-digital conversion device comprising:
a signal generating unit configured to generate a plurality of comparison voltages based on an analog input voltage and to generate a plurality of comparison results with respect to the plurality of comparison voltages based on a sampling period;
a calculation unit configured to skip a comparison result generated by a comparison voltage having a smallest difference between the analog input voltages among the plurality of comparison voltages from the plurality of comparison results, and to generate an end of comparison based on a remaining plurality of comparison results; and
a SAR logic unit configured to generate a digital signal corresponding to the end of comparison and to store information for each bit of the digital signal,
wherein the signal generating unit comprises:
a comparison unit configured to invert a phase of at least one of the plurality of comparison voltages to generate a plurality of enlarged comparison voltages, and to output the plurality of comparison results based on the plurality of enlarged comparison voltages.
2 . The analog-to-digital conversion device of claim 1 , wherein the signal generating unit includes:
a sampling/hold circuit configured to sample the analog input voltage to a sampling voltage based on the sampling period; and
a converter circuit configured to convert the sampling voltage into the plurality of comparison voltages.
3 . The analog-to-digital conversion device of claim 2 , wherein the converter circuit performs a capacitor switching operation for adjusting the sampling period of the sampling voltage.
4 . The analog-to-digital conversion device of claim 1 , wherein the analog-to-digital conversion device is configured to detect a predetermined range in the sampling period.
5 . The analog-to-digital conversion device of claim 1 , wherein the end of comparison is output as a logic high level or a logic low level.
6 . A method of operating an analog-to-digital conversion device, the method comprising:
generating a plurality of comparison voltages based on an analog input voltage, and generating a plurality of comparison results with respect to the plurality of comparison voltages based on a sampling period;
skipping a comparison result generated by a comparison voltage having a smallest difference between the analog input voltages among the plurality of comparison voltages from the plurality of comparison results, and generating an end of comparison based on a remaining plurality of comparison results; and
generating a digital signal corresponding to the end of comparison and storing information for each bit of the digital signal,
wherein the generating of the plurality of comparison results comprises inverting a phase of at least one of the plurality of comparison voltages to generate a plurality of enlarged comparison voltages, and outputting the plurality of comparison results based on the plurality of enlarged comparison voltages.
7 . The method of claim 6 , wherein the generating of the plurality of comparison results includes:
sampling the analog input voltage to a sampling voltage based on the sampling period; and
converting the sampling voltage into the plurality of comparison voltages.
8 . The method of claim 7 , wherein the converting of the sampling voltage into the plurality of comparison voltages includes:
performing a capacitor switching operation for adjusting the sampling period of the sampling voltage.
9 . The method of claim 6 , wherein the method of operating the analog-to-digital conversion device includes detecting a predetermined range in the sampling period.
10 . The method of claim 6 , wherein the end of comparison is output as a logic high level or a logic low level.